The District's campaign finance regulators have completed their audit of D.C. Mayor Vincent Gray's 2010 campaign, but they declined to say Monday when the probe's findings will be released to the public.

"The final audit report has been completed," the D.C. Office of Campaign Finance said in a report it quietly issued earlier this month. "However, at the request of the U.S. Attorney's Office, additional information may be necessary."

Wesley Williams, an agency spokesman, said campaign finance regulators did not have a timeline for public distribution of the audit, which the report said was "contingent upon coordination with another enforcement agency."

Bill Miller, a spokesman for U.S. Attorney Ronald Machen Jr., declined to comment on the District's investigation, which took more than two years to complete.

Local and federal authorities began probing the campaign in March 2011 after a minor mayoral candidate, Sulaimon Brown, went public with allegations that he had been paid to remain in the contest so he could criticize Adrian Fenty, the incumbent and Gray's rival.

Gray, who has not been charged with a crime and largely avoided discussing the investigations, quickly denied wrongdoing and said his campaign had not acted improperly.

Prosecutors have since secured guilty pleas from two of Gray's campaign aides who acknowledged their roles in the scheme.

The federal investigation is ongoing, and Miller said in December that prosecutors had "much more to do in 2013." Local investigators appeared ready last summer to release their findings when Williams told The Washington Examiner that the audit report was "under review subject to final issuance."

But within two months -- after prosecutors detailed the existence of a $653,800 shadow campaign that benefited the mayor -- the agency postponed the report's release indefinitely.